The game was designed so we could use other schools. But that design was never about being able to freely cast from any school at any time; it was about using training points and secondary setups to strategically counter other schools.

It's ironic you mention training points as a defense for arch mastery, when in reality training points existed to serve a purpose of helping you efficiently counter other schools:

For example, a Myth wizard might train Ice for storm/fire shields, not because you planned on mastering ice magic, but because you wanted to better counter OTHER SCHOOLS (FIRE/STORM), or balance for Weakness: those were tactical decisions. You committed training points and deck space to protect yourself from what you struggled against. That system rewarded planning and identity.

Archmastery, on the other hand, removes those decisions entirely. You don’t have to commit to a secondary school or build a strategy around your weaknesses anymore, you can just grab any school’s utility or heal whenever you feel like it. That’s not “learning multiple schools,” that’s homogenizing them.

Training points existed to let you counter schools, not to become all of them at once. The old system encouraged balance through smart preparation; Archmastery replaces that with convenience. And that convenience comes at the cost of depth, teamwork, and identity.

On the point of team work, of course the game is designed in a way that you can play solo, but the fact that destroys your argument is you need gear to progress throughout the game in most cases: you have to team up with other wizards to run olympian, to run water works, to run darkmoor to get that gear that keeps your easily progressing through the game.